In recent years, a technique in which a number of bare chips of semiconductor light-emitting elements are mounted on a circuit board, typically represented by a light emitting diode (hereinafter, referred to as “LED”), to manufacture illuminating and display devices or the like has been widely utilized. With respect to the mounting technique for mounting the bare chips for the LED (hereinafter, referred to as “LED chip”) on a circuit board, a flip chip junction utilizing bumps, for example, described in Patent Document 1 and Patent Document 2, has been generally used.
FIG. 16 is a cross-sectional view that schematically shows a state in which LED chips having a typically conventional structure are mounted on a circuit board. FIG. 17 is a bottom view of the conventional LED chip. FIG. 16 is the drawing that schematically shows a cross section taken along line C-C of FIG. 17.
An LED chip 101 has a light-transmitting substrate 111 (hereinafter, referred to as “element substrate”), an n-type semiconductor layer 112 formed on the element substrate 111 so as to cover the element substrate 111, a p-type semiconductor layer 113 formed so as to cover an area on the n-type semiconductor layer 111a from which an area 112a for an n-electrode (see FIG. 17) on the corners of the n-type semiconductor layer 112 is excluded, an n-electrode 114 formed on the area 112a for the n-electrode on the n-type semiconductor layer 112, and a p-electrode 115 formed on the p-type semiconductor layer 113.
The LED chip 101 is electrically connected to a circuit board 140 by respectively joining the n-electrode 114 and the p-electrode 115 to a plurality of bumps 142 formed on the electrode 141 on the circuit board 140 by utilizing ultrasonic waves. The LED chip 101, thus electrically connected to the circuit board 140, is allowed to emit light when an electric current flows through a pn junction 123 between the n-type semiconductor layer 112 and the p-type semiconductor layer 113.
Patent Document 1: Japanese Unexamined Patent Publication No. 11-161197
Patent Document 2: Japanese Unexamined Patent Publication No. 11-354836